The FBW a320 and PMDG 737 are pretty much unflyable because you can’t see out of the windshield because of Icing with real weather. I turn on window heat but the windshield doesn’t clear in either plane.
Is anyone else noticing this?
Is there a fix?
Bill
Had the same with the FBW a320, didn’t try the PMDG 737. The JF BAe 146 handled it better. When I took bleed air from the engines the icing breaks down after a while on the ground, while it stayed in the a320. Same airport (LFSB) with live weather, about 10 min difference.
The GSX pro anti- icing helped me on the next flight in the a320, another fix could be to change the weather from live (or any cold preset) to a warm summer day and wait a while. Not a clean and an immersion breaking fix, but it works…
Make sure you activate anti-ice measures inside the sim BEFORE you get into icing conditions. That makes it a bit easier for the sim to handle things realistic.
Mathijs Kok
PMDG
For the 737, the only icing issue I encounter is when icing conditions occur on the ground. Soon as I spawn in, it’s already icing so by the time you get powered up (from Cold and Dark) the windows are iced.
Turning on the Windshield Heat doesn’t do much at the gate, you have to get the APU going and it will start to clear.
Thanks, I’ll give these suggestions a try.
Bill
For the FBW A32NX, update to the latest dev version. The time to deice the windscreen has been reduced from the default Asobo deicing rate that takes nearly 8 minutes to 30 seconds.
Window heat on the A320neo is automatic with at least one engine running. With engines off, you can activate it via the PROBE/WINDOW HEAT pushbutton switch in the overhead.
You can get the APU up in about a minute after loading into the 737. Or grab the ground Power quick.
Ground power doesn’t do anything for the icing, need the air from the APU to get the windows to start clearing.
Just to make sure: APU on alone won‘t help, you need to turn on bleed air as well. Not sure if the Airbus opens the valve itself but in the 737 you need to do it yourself on the right side of the overhead. It could be you need to open further valves, I‘m not fluent in „737 talk“ 
Mathijs, can you please explain what you mean by " Make sure you activate anti-ice measures inside the sim"
Bill
I found two links that discuss Icing.
Bill
For the FBW, you may have wanted to link this: Ice and Rain Protection - FlyByWire Simulations Documentation and this: Reported Known Issues - FlyByWire Simulations Documentation
Sure.
A lot of the ant-ice systems will have problems removing ice buildup after it has grown in certain conditions. Use the anti-ice systems to prevent ice works a lot better.
There really isn’t any “anti-ice” simulated in MSFS. Only de-ice. But if you get it on early, depending on what rate the developer has chosen for de-icing, it can counteract the icing or at least keep it from getting worse.
Some really good information on Icing in this post. I think the key is to De-ice on the safe side depending on the weather. Use all the anti-icing options listed above to assist, however, there will be times when it won’t be enough based on sim actual weather dynamics and you shouldn’t fly that route. The issue is you won’t know until it starts Icing. At least you won’t kill everyone in the sim if you crash. Not sure if developers can assist in this area.
I am not a real pilot so I can’t speak to real-life procedures. Who makes the call not to fly and how to determine go or no go?
Bill
I stumbled on this thread as I was troubleshooting my own icing anomalies in the Fenix A320.
So, a couple of things from my time in the Bus and Boeing (bear in mind that I haven’t flown a RL 737 in about 14 years):
As far as I can remember, both AC have electrically heated windows (i.e. they work more like your car’s rear window than your front). There are some AC that have hot air blowing on your front windscreen, but I don’t remember that being the case in either of these two AC. At least, not as your primary defrosting mechanic.
FWIW, I flew the B-737-200/300/500/700 (so…older) and the A319/320/321 (newer and more recently), just as a gauge.
As such, I’m a little confused about the comment that turning on your APU is necessary to deice the AC, particularly the windows for the reason I stated. For one thing, I seem to recall that the engine AI in either AC is provided by its own bleed air, usually through a primary and auxiliary bleed valve. So, I’m not even certain that you could get APU air to either EAI system.
As far as WAI goes, I believe both the Bus and Boeing use air from the bleed system (to which the APU is attached through its own bleed valve). But, considering that in either case the only thing that you are applying heat to are portions of the leading edge, you’re not really deicing much. Moreover, I know that the Bus cautions you against using APU bleed to deice the wings. I wouldn’t be surprised (but can’t remember) if the 737 wasn’t the same.
That all being said, with the exception of a cold and dark start on a snowy ramp, the electrically heated windows always seemed to work famously…for the same reason they work on your rear window. Bear in mind that I have primarily flown in CONUS; a Norwegian Bus/Boeing driver may give you a different answer! 
None of that will have any effect on the rest of your aircraft however. It will be covered by snow and ice until you deice it. It really can’t be deiced by itself. The primary initial concern is usually the engines. I’ve heard of various methods of defrosting them (e.g. hot air) but, if you can get her off the gate, then you can taxi down to the deicing pits.
Once there, you should have most of your concerns addressed…at least until the holdover time has expired.
There are, of course, things you must consider when you’re operating in these conditions, but generally it works quite well.
As to filing/operating in icing conditions enroute, the dispatcher and pilot in command share joint operational authority. Bear in mind that, just because there is icing forcasted/reported in an area, that doesn’t mean that it is occurring at all altitudes within that area. For instance, yesterday there was a wide swath of moderate icing forecast along the US eastern seaboard, but only between the surface and 20,000ft. Since most jet flights operate above that altitude, there’s likely no reason that enroute operations couldn’t fly through there.
Moreover, just because there is icing forecast in an area, doesn’t mean that aircraft can’t operate there at all. It just means that flight crews and controllers may need to consider, plan for, and be prepared for icing to occur.
I wouldn’t want to fly a C-152 through those areas. But most airliners are capable of operating in at least moderate icing conditions…with potentially some restrictions.
On the other hand, all the operators that I have worked for have had a prohibition (likely FAA standard) against operating in known or forecast severe icing conditions. Luckily, that doesn’t occur very often…at least in temperate latitudes.
Lastly, and I apologize for how long this is, from the reason that I found myself here, I think that MSFS can exaggerate icing a bit. Flying the excellent Fenix A320, I encountered icing at approach altitudes in both IAD and LGA in the last two days that overwhelmed the pitot heating capability of the Bus. Historically, this isn’t unheard of, but it feels unlikely on two subsequent days.
I understand from reading above that this is a Fenix…ism. But, having switched to the default Asobo A320, it shortly did the same thing.
So, just something to keep in mind when you are flying these larger, more capable, aircraft in MSFS that things may be modelled more, dramatically, than is strictly accurate. 
My answer is rubbish but if you’re able to complete your flight under IFR conditions, you’re king.
Something with auto-land.
Make sure to have engines, wings and pitot tubes free of ice before the so called buttering the bread.
Excellent information thank you. I didn’t realize it was electric window heat. Maybe developers could look at it. This is the first winter I’ve noticed it like this with the extremely cold air coming down from the north.
Bill
It may also just be that, lacking any other obvious visual cues, MSFS may have chosen window frosting as it’s representation of all icing, rather than trying to show window icing as such.
I don’t know if you saw it, but I gave you the answer for the FBW A32NX. The FBW developers have already looked at it and provided a sim usable, yet realistic solution.